Mac (Bluetooth): Previously mentioned Type2Phone has received a big update that enables you to use your Mac's dictation feature to convert speech to text and send it over Bluetooth to any compatible device. Additionally, the app now accepts AppleScript input, so you can send special commands.
Although primarily a Mac app designed for using your computer's keyboard on your iPhone or Apple TV, Type2Phone works fine on other platforms as well. I've been able to type just fine on my Nexus 4. Dictation works just like it does in any other Mac app — you simply press the function key twice to start speaking, and then press it once more when you're finished. The computer will handle the conversion and send the text directly to your device.
Type2Phone can now handle input beyond plain text, meaning you can send commands to control devices. This only seems to work with Apple devices, as designed, but it helps with one of the app's larger downsides. Previously, you couldn't move around your phone via the computer, and you had to tap buttons to send what you typed, or just move throughout certain fields on the screen. Now, Type2Phone can emulate that functionality.
You don't have to know AppleScript to do it — many of the functions are built into Type2Phone's special menu. Of course, if you want to create custom functions, you can write them yourself.
Like before, Type2Phone will set you back $5.49. If you bought it in the past, however, this update is free.
Type2Phone ($5.49) [Mac App Store]